A tissue graft packaging system having a retainer including first and second members with respective first and second pluralities of channel sidewalls that define first and second pluralities of channels, and first and second engagement means configured to removeably interconnect the first and second members. The first and second pluralities of channel sidewalls are configured to create a continuous interior space between the first and second members. A tissue graft, such as a cryopreserved viable tissue graft, is contained within the continuous interior space of the retainer. Processes for packaging, thawing and rinsing the tissue graft using the tissue graft packaging system and its retainer are also disclosed.